Cooling arrangement for an automotive internal combustion engine



May 9, 1967 s. MOBiUS 3,318,526

, COOLING ARRANGEMENT FOR AN AUTOMOTIVE INTERNAL COMBUSTION ENGINE Filed July 15, 1965 4 Sheets-Sheet 1 lNVENI' 01? y 1967 s MOBIUS 3,318,526

COOLING ARRANGEMENT FOR AN AUTOMOTIVE INTERNAL COMBUSTION ENGINE Filed July 15, 1965 4 Sheets-Sheet 2 y 1967 s. MCBIUS 3,318,526

. COOLING ARRANGEMENT FOR AN AUTOMOTIVE INTERNAL COMBUSTION ENGINE Filed July 15, 1965 4 Sheets-Sheet (5 wmvmp May 9, 1967 s. MGBIUS 3,318,526

COOLING ARRANGEMENT FOR AN AUTOMOTIVE INTERNAL COMBUSTION ENGINE Filed July 15, 1965 4 Sheets-Sheet 4 United States Patent Ofiice 3,318,526 Patented May 9, 1967 3,318,526 COOLING ARRANGEMENT FOR AN AUTOMO- TIVE INTERNAL COMBUSTION ENGINE Siegfried Miihius, Schweinfurt am Main, Germany, as-

signor to Fichtel & Sachs A.G., Schweinfurt am Main, Germany, a corporation of Germany Filed July 15, 1965, Ser. No. 472,367 Claims priority, application Germany, July 17, 1964, F 43,465 13 Claims. (Cl. 236-35) This invention relates to water-cooled automotive internal combustion engines, and particularly to a thermostat-controlled fan arrangement for drawing air through a radiator provided for heat exchange between the cooling water and ambient air.

In most automobiles having water-cooled internal combustion engines, the radiator for the cooling water is arranged ahead of the engine in the normal direction of vehicle movement, and a fan driven by the engine draws air through the radiator which has normally a honeycomb structure. The rate of cooling provided by the tau-propelled air is too high when the ambient air is unusually cold, when the engine is still cold, and under other conditions of operation. It is therefore known to interpose a clutch between the fan and the engine drive and to control the clutch by a thermostat.

A known clutch-driven fan arrangement has a thermostatwhich is axially mounted on the fan in the space between the fan and the radiator. The clutch is engaged when the thermostat senses a certain temperature which may be set, but the temperature sensed by the thermostat in the known device is not equally indicative of the actual water temperature in the radiator under different conditions of operation. The vehicle speed, significantly affects the relationship between the water temperature and the sensed temperature, and the relationship may also be affected by the temperature of the engine block which is normally located closely below the fan and thermostat.

An object of the invention is the provision of a cooling arrangement of the type described in which a fan clutch is engaged and disengaged by a thermostat at temperatures uniquely related to the actual temperature of the cooling water in the radiator.

A more specific object is the provision of such an arrangement in which the response of the thermostat is not significantly affected by the vehicle speed.

It has been found that the temperature of the air which passes through the openings in the usual automotive radiator is closely related to the water temperature, and only insignificantly affected by other variables, and that the desired correlation between water temperature and thermostat response can be obtained if the clutch controlling thermostat is exposed predominantly to air flowing through the radiator, and is protected against air flowing around the radiator or coming from other directions.

. The invention, in one of its aspects, therefore provides a battle which is arranged so that it enhances flow of passing air in a direction from the radiator to the clutch actuating thermostat and reduces flow of air to the thermostat from all other directions. The eifectiveness of the device is directly related to the extent to which it enhances the desired type of air how and reduces unwanted air flow. Other features and many of the attendant advantages of this invention will be readily apparent from the fOllOW- ing description of preferred embodiments when taken with the attached drawings in which:

FIG. 1 is a fragmentary side-elevational view of a watercooling unit of the invention in an otherwise conventional automotive engine;

FIG. 2a shows a modified battle for the unit of FIG. 1;

FIG. 2b illustrates yet another modification of the baffle in the unit of FIG. 1;

FIG. 3 shows another cooling unit in a partly sectional side-elevational view;

FIG. 4 illustrates a further unit in a similar View;

FIGS. 5 to 8 show additional cooling units of the invention which differ from each other in the shape and/ or arrangement of the bafile.

Referring first to FIG. 1, there is shown as much of an automotive vehicle as is needed for an understanding of this invention. The output shaft, not itself visible, of a clutch 1, carries a fan 22 and a thermostatic clutch actuator 2 of a type well known in itself. The temperature response of the actuator can be varied in a known manner by turning a ring 23. The input shaft of the clutch 2 is connected to the engine of the vehicle in a conventional manner not illustrated.

The radiator 3 of the engine is arranged just ahead of the thermostatic actuator 2 and the fan 22. The air flow about the actuator 2 is controlled in a simple, but effective manner by a flat circular baffle plate 5 which is spacedly attached to the front face of the radiator 3 by brackets 4. The presence of the plate 5 in the indicated position causes intense turbulence in the corresponding air space behind the radiator 3 in which the thermostatic clutch actuator 2 is located. The air in the turbulent zone consists almost exclusively of air which has just passed the radiator in the direction of the arrow F, and air coming from any other direction is eifectively excluded.

' Similar, and sometimes better results are achieved with bafiles of different shape but mounted in the same manner as the plate 5. FIGS. 2a and 2b respectively show cupshaped batfies 6, 7 of sheet metal made into a hollow spherical cap and into a hollow cone. The cavities of the baifies 6, 7 are open in the direction of the arrow F.

Whereas the bafiie members 5, 6, 7 are effective by their turbulence producing arrangement, the cylindrical tubular member 8 utilized in the otherwise identical cooling arrangement shown in FIG. 3 minimizes turbulence in the air flow about the thermostatic clutch actuator 2. The bafile member 8 is mounted on the rear face of the radiator 3 in such a manner that it is approximately coaxial with the fan, the clutch, and the actuator 2. The latter and its adjusting ring are received in the open rear end of the bafiie member 8 so as to define therewith a narrow annular gap 9.

The air velocity outward of the member 8 at the gap 9 is high enough under all practical conditions of operation to exclude air not coming directly from the radiator 3 from contact with the actuator 2.

In the modified arrangement shown in FIG. 4, the bafiie member 10 is approximately funnel-shaped and tapers in the direction of normal air flow. Only the free axial end of the actuator 2 is received in the narrow end of the baffle member 10, but the air velocity out of the annular gap 11 between the battle member 10 and the actuator 2 is high enough to ensure that the actuator is fully enveloped at all times by air coming directly from the radiator 3.

The devices shown in FIGS. 3 and 4 are limited to applications in which relative movement of the fan unit and of the radiator transversely of the fan axis is narrowly limited. It the fan is directly mounted on the engine, and

the engine is provided with resilient mountings, the necessary alignment of the baffie members with the clutch actuator is not always maintained. p

FIGS 5 to 8 show baffle arrangements not limited in their application by such considerations. The bafile member 12 shown in FIG. 5 a cylindrical cup whose bottom is apertured and internally threaded for mounting engagement with corresponding external threads on the adjusting rin 23 of the thermostatic clutch actuator 2.

'e wide open front end of the baffle member 12 may be located closely adjacent the rear face of the radiator 3 since the engine vibrations have a very small component in the direction of vehicle movement. Ai'r admitted from the radiator to the cavity of the bafile member is dis charged through radial openings 13 near the bottom of the cavity. The entire exposed surface of the thermostatic actuator 2 is located within the cavity.

No air can enter the space within the baffle member 13 through the openings 13 against the rapid outward air stream, and very little air not directly com-ing from the radiator 3 is drawn into the baffie member 12 through the narrow gap between its open end and the radiator.

The proportion of such outside air is further reduced in the arrangement shown in FIG. 6 whose bathe member 14 tapers in a direction from the radiator 3 toward the radial openings 15 in the bottom of the baffle cavity. The baffle member draws more air from the radiator 3 than the baffle member 12 shown in FIG. 5 under otherwise identical conditions, and thus further reduces the proportion of air reaching the actuator 2 from any direction other than directly from the radiator openings.

The coolingqarrangement illustrated in FIG. 7 has a bafiie member 16 which differs from the cylindrical tubular member 12 shown in FIG. 5 by the provision of vanes 17 arranged on the inner wall of the bafile member near its open end. The vanes rotate with the fan on which the bafiie member 16 is mounted and draw air from the radiator 3 to the clutch actuator 2. This arrangement produces a particularly rapid response of the actuator to changes of water temperature in the radiator 3. The vanes 17 counteract the throttling effect of the restricted radial passages 18 throngh which the air leaves the bathe member 16, and prevent diversion of air from the radiator 3 around the bafiie member 16 and the clutch actuator 2 a received therein.

A similar effect is achieved in the baffie member 19 shown in FIG. 8 by an inner bafiie wall which has a conthrough radial openings 21 in the same manner 'as described above.

The outer wall of the baflie member 19 is conical so that the inner and outer walls are obliquely inclined relative to each other, and the wall thickness increases from the open rear end of the baflie member 19 to the throat 20, and then decreases sharply from there in a forward direction. The heavy metal section which surrounds the throat remains at an elevated temperature for some" time after the temperature of the water in the radiator 3 and of the 'air in the throat 20 has dropped to a temperature below that for which the thermostatic actuator 2 is set to disengage the drive clutch of the fan. A delayed disengagement of the fan from the engine drive under such conditions is frequently desirable, and is achieved in a particularly simple manner with the annular heavy Wall portion surrounding the throat 20 in the bathe member 19. It will be appreciated that heat transfer from the hot wall to the actuator 2 during the period of delay is mainly due to radiation.

Various modifications are contemplated and may obviously be resorted to by those skilled in the art without departing from the spirit and scope of the invention as hereinafter defined by the appended claims as only preferred embodiments thereof have been disclosed.

What is claimed is:

1. In an automotive vehicle, in combination:

(a) an automotive-type radiator arranged for passage of air therethrough in a predetermined direction during normal movement of said vehicle;

(b) fan means spaced from said radiator in said direction for drawing air through said radiator;

(c) disengageable clutch means for driving said fan means;

(d) temperature responsive clutch actuating means interposed between said fan means and said radiator and exposed to the how of ambient 'air for engaging and disengaging said clutch means in response to ambient air temperature; and

(e) bafiie means for enhancing flow of passing air in a direction from said radiator to said actuating means and for reducing flow of air to said actuating means from all other directions, said baffle means including a bafiie member extending transversely of'said predetermined direction and aligned with said actuating means in said direction, said baffle member" being mounted on said radiator, and being offset from said radiator in a direction away from said actuating means.

2. In a vehicle as set forth in claim 1, said baflle member being a substantially flat plate.

3. In a vehicle as set forth in claim 1, said bafiie member being substantially cup-shaped anddefining a cavity open in said predetermined direction. 7

4. In an automotive vehicle, in combination: 7

(a) an automotive-type radiator arranged for passage of air therethrough in a predetermined direction during normal movement of said vehicle;

(b) fan means spaced from said radiator in said direction for drawing air through said radiator;

(c) disengageable clutch means for driving said fan 7 means;

terposed between said fan means and said radiator andexposed to the flow of ambient air for engaging and disengaging said clutch'means in response to the temperature of said ambient air; and 4 (e) a substantially straight tubular bafiie member having an axis directed from said radiator toward said actuating means, one axial end of said tubular member being open toward said radiator, and the other axial end of said tubular member being formed with an opening for defining a path of air flow extending axially through said tubular member, a temperature sensitive portion of said actuating means being located in said path.

5. In a vehicle as set forth in claim 4, said fan means.

including a fan member, and means for rotating said fan 2 member about said axis.

6. In a vehicle as set forth in claim 4, a portion of said actuating means being received in said tubular memher.

7. 'In a vehicle as set forth in claim 6, said tubular termined direction from at least a part of the received portion of said actuating means.

9. In a vehicle as set forth in claim 8, fastening means fixedly securing said tubular member to said actuating means.

10. In a vehicle as set forth in claim 4, said tubular member having a substantially cylindrical inner wall.

11. In a vehicle as set forth in claim 4, said tubular member having an inner wall tapering in said predetermined direction.

12. In a vehicle as set forth in claim 4, said tubular member having an inner Wall and a plurality of vanes projecting from said wall toward said axis.

13. In a vehicle as set forth in claim 4, an inner Wall of said tubular member having a converging axial portion and a diverging axial portion extending from said converging portion in said predetermined direction and defining a throat therewith, a portion of said actuating means being located in said throat.

References Cited by the Examiner UNITED STATES PATENTS Wolfram.

10 EDWARD 1. MICHAEL, Primary Examiner. 

1. IN AN AUTOMOTIVE VEHICLE, IN COMBINATION: (A) AN AUTOMOTIVE-TYPE RADIATOR ARRANGED FOR PASSAGE OF AIR THERETHROUGH IN A PREDETERMINED DIRECTION DURING NORMAL MOVEMENT OF SAID VEHICLE; (B) FAN MEANS SPACED FROM SAID RADIATOR IN SAID DIRECTION FOR DRAWING AIR THROUGH SAID RADIATOR; (C) DISENGAGEABLE CLUTCH MEANS FOR DRIVING SAID FAN MEANS; (D) TEMPERATURE RESPONSIVE CLUTCH ACTUATING MEANS INTERPOSED BETWEEN SAID FAN MEANS AND SAID RADIATOR AND EXPOSED TO THE FLOW OF AMBIENT AIR FOR ENGAGING AND DISENGAGING SAID CLUTCH MEANS IN RESPONSE TO AMBIENT AIR TEMPERATURE; AND (E) BAFFLE MEANS FOR ENHANCING FLOW OF PASSING AIR IN A DIRECTION FROM SAID RADIATOR TO SAID ACTUATING MEANS AND FOR REDUCING FLOW OF AIR TO SAID ACTUATING MEANS FROM ALL OTHER DIRECTIONS, SAID BAFFLE MEANS INCLUDING A BAFFLE MEMBER EXTENDING TRANSVERSELY OF SAID PREDETERMINED DIRECTION AND ALIGNED WITH SAID ACTUATING MEANS IN SAID DIRECTION, SAID BAFFLE MEMBER BEING MOUNTED ON SAID RADIATOR, AND BEING OFFSET FROM SAID RADIATOR IN A DIRECTION AWAY FROM SAID ACTUATING MEANS. 